Socially and professionally, most people rely on visual display systems of one form or another for at least a portion of their work and/or recreation. Typical displays, such as cathode ray tubes (CRTs), plasma display panels (PDPs) and the like are opaque, or at the very least block the view of background objects directly behind the display system.
See-through display technology for the display of text messages has been advancing, but is primarily limited to the fields of advertising and teleprompting for news and presentation. In advertising, such systems are desirable as they permit a customer to receive text information while viewing actual items such as retail clothing. For news media, teleprompters permit the presenting party to appear as though he or she is maintaining eye contact with the audience. Heads-up see-through displays are also evolving in for use in aircraft and automobiles as they permit the operator of the plane or vehicle to maintain visual awareness of the outside environment while receiving important information such as speed, direction, remaining fuel, etc.
These see-through display systems or heads-up displays are typically achieved by using a transparent piece of glass or plastic mounted at a forty five degree angle. In some configurations there is also a thin coating of reflective material, sufficient to establish a half mirror. With such systems, the projected information is presented only to one side of the display. Thus, for example, the audience does not see the speech scrolling across the teleprompter.
Such systems are reasonably good for high contrast material such as bright text, or images formed of localized bright lines. These systems are poor in the ability to provide sufficient contrast and brightness for gray-scale or full color imagery. In addition, the typical forty five degree tilt results in a rather bulky structure that not suitable for installation in settings where compactness and intimacy might be important. Further, such systems have an extremely narrow field of view—an observer directly in front of the screen can see the text or information, but an observer standing directly to one side or the other may not, or at the very least will perceive a dramatically dimmer image. In addition, such displays can not be placed directly upon a background object such as a map or chart, without the background object then being viewed at an undesirable angle.
Weight, thickness, durability, cost, aesthetic appearance and quality are key considerations for display systems, including see-through systems. Hence, there is a need for a device that overcomes one or more of the drawbacks identified above.